1. Field of the Invention
This invention relates to a string instrument and more particularly to a guitar.
2. Description of the Related Art
The design of modern guitars has remained relatively unchanged for many years. A traditional guitar is comprised of a body which is connected to a neck and has a plurality of strings strung at a substantial tension extending from a fixed point at the guitar neck to the bridge located on the lower region of the guitar body. The top of the neck on a traditional guitar contains a fretboard which is normally made of a hardwood or alternate substance such as maple, rosewood, ebony, or a re-enforced polymer. The material should be strong enough and stable enough to hold metal frets and be able to withstand playing wear.
Normally, the strings are tuned to pitch at the top of the neck or “headstock” where tuning pegs increase or decrease the tension on each string. The user then renders the desired notes by strumming the strings near the middle of the guitar body while pressing the strings which extend over the neck onto a fretboard attached to the upper surface of the neck. The tone of the note produced depends on the tension of the string and the distance between the fret at which the string is depressed onto the neck and the lower anchor point. The smaller the distance between the depressed string and the bridge, the higher pitch the resulting tone will be. Increasing the tension of the strings will also produce a note with a higher pitch.
An important aspect to the playability of a stringed instrument is the distance that the string lies above the neck. The height of the string relative to the neck and the fretboard is commonly referred to as a string's “action.” Typically, the desired action on a guitar is subject to each user's personal preference. Certain musicians prefer to have a smaller distance between the fingerboard and the strings or “low” action while others require a high action in order to avoid fret buzzing, amongst other considerations. In general, very minute differences in the height that the string is above the neck can make a major difference on the performance of amateur and professional musicians alike.
On a traditional guitar, the action of the instrument is usually set at the factory and changes to the action must be made by an experienced technician. Furthermore, the traditional guitar normally has a very limited range of movement and significant changes to the action of the instrument may only be able to be accomplished by modifying the structure of the body or neck of the instrument. These type of modifications can be quite costly and can have a serious effect on the guitar's long term performance.
Consequently, it is desired to have a musical instrument that allows the user to quickly and efficiently adjust the action on the instrument.
The prior art references several string instruments which change the action of the instrument by adjusting the angle of inclination the neck extends from the guitar body. These devices rely on the principal that when the angle between the neck and the body is increased the action is lowered and when the angle is decreased the action is raised. However, while the action can be raised or lowered by adjusting the angle between the neck and the body of the guitar, changing angle of the neck relative to the body also effects the intonation, tonal properties and scale lengths of the guitar strings. The disadvantage to these designs is that the user cannot adjust the action of the neck without altering the intonation and sound of the guitar.
For instance, U.S. Pat. No. 6,051,766 discloses a guitar where the neck angle is changed relative to the guitar body by placing shims of varying widths into the guitar cavity that the neck is secured to the guitar body. Another adjustable neck is disclosed in U.S. Pat. No. 6,265,648 which provides for a neck secured to the guitar body via a spring-loaded clamping device that creates a pivot point allowing for movement of the neck at an angle relative to the body. Both of these devices do not permit the user to adjust the vertical direction of the neck without also changing the angle of the neck relative to the body. Furthermore, the U.S. Pat. No. 6,051,766 patent requires the user to disassemble the neck from the guitar body in order to adjust the action of the guitar strings. Additionally, the U.S. Pat. No. 6,265,648 patent relies on a spring's biasing force to hold the neck in place. This force of the spring is likely to degrade over time rendering the neck unstable. The force provided by the string also creates an upward force on the neck-body joint which can lead to damage of various structures on the guitar.
Consequently it is desired to have a neck which can be easily adjusted in a vertical direction without affecting the angle that the neck extends from the body.